summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/snic/snic_trc.c
blob: f23fe2f884389cb48cc5a6ec29d638ea627625e0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/module.h>
#include <linux/mempool.h>
#include <linux/errno.h>
#include <linux/vmalloc.h>

#include "snic_io.h"
#include "snic.h"

/*
 * snic_get_trc_buf : Allocates a trace record and returns.
 */
struct snic_trc_data *
snic_get_trc_buf(void)
{
	struct snic_trc *trc = &snic_glob->trc;
	struct snic_trc_data *td = NULL;
	unsigned long flags;

	spin_lock_irqsave(&trc->lock, flags);
	td = &trc->buf[trc->wr_idx];
	trc->wr_idx++;

	if (trc->wr_idx == trc->max_idx)
		trc->wr_idx = 0;

	if (trc->wr_idx != trc->rd_idx) {
		spin_unlock_irqrestore(&trc->lock, flags);

		goto end;
	}

	trc->rd_idx++;
	if (trc->rd_idx == trc->max_idx)
		trc->rd_idx = 0;

	td->ts = 0;	/* Marker for checking the record, for complete data*/
	spin_unlock_irqrestore(&trc->lock, flags);

end:

	return td;
} /* end of snic_get_trc_buf */

/*
 * snic_fmt_trc_data : Formats trace data for printing.
 */
static int
snic_fmt_trc_data(struct snic_trc_data *td, char *buf, int buf_sz)
{
	int len = 0;
	struct timespec64 tmspec;

	jiffies_to_timespec64(td->ts, &tmspec);

	len += snprintf(buf, buf_sz,
			"%llu.%09lu %-25s %3d %4x %16llx %16llx %16llx %16llx %16llx\n",
			tmspec.tv_sec,
			tmspec.tv_nsec,
			td->fn,
			td->hno,
			td->tag,
			td->data[0], td->data[1], td->data[2], td->data[3],
			td->data[4]);

	return len;
} /* end of snic_fmt_trc_data */

/*
 * snic_get_trc_data : Returns a formatted trace buffer.
 */
int
snic_get_trc_data(char *buf, int buf_sz)
{
	struct snic_trc_data *td = NULL;
	struct snic_trc *trc = &snic_glob->trc;
	unsigned long flags;

	spin_lock_irqsave(&trc->lock, flags);
	if (trc->rd_idx == trc->wr_idx) {
		spin_unlock_irqrestore(&trc->lock, flags);

		return -1;
	}
	td = &trc->buf[trc->rd_idx];

	if (td->ts == 0) {
		/* write in progress. */
		spin_unlock_irqrestore(&trc->lock, flags);

		return -1;
	}

	trc->rd_idx++;
	if (trc->rd_idx == trc->max_idx)
		trc->rd_idx = 0;
	spin_unlock_irqrestore(&trc->lock, flags);

	return snic_fmt_trc_data(td, buf, buf_sz);
} /* end of snic_get_trc_data */

/*
 * snic_trc_init() : Configures Trace Functionality for snic.
 */
int
snic_trc_init(void)
{
	struct snic_trc *trc = &snic_glob->trc;
	void *tbuf = NULL;
	int tbuf_sz = 0, ret;

	tbuf_sz = (snic_trace_max_pages * PAGE_SIZE);
	tbuf = vzalloc(tbuf_sz);
	if (!tbuf) {
		SNIC_ERR("Failed to Allocate Trace Buffer Size. %d\n", tbuf_sz);
		SNIC_ERR("Trace Facility not enabled.\n");
		ret = -ENOMEM;

		return ret;
	}

	trc->buf = (struct snic_trc_data *) tbuf;
	spin_lock_init(&trc->lock);

	snic_trc_debugfs_init();

	trc->max_idx = (tbuf_sz / SNIC_TRC_ENTRY_SZ);
	trc->rd_idx = trc->wr_idx = 0;
	trc->enable = true;
	SNIC_INFO("Trace Facility Enabled.\n Trace Buffer SZ %lu Pages.\n",
		  tbuf_sz / PAGE_SIZE);
	ret = 0;

	return ret;
} /* end of snic_trc_init */

/*
 * snic_trc_free : Releases the trace buffer and disables the tracing.
 */
void
snic_trc_free(void)
{
	struct snic_trc *trc = &snic_glob->trc;

	trc->enable = false;
	snic_trc_debugfs_term();

	if (trc->buf) {
		vfree(trc->buf);
		trc->buf = NULL;
	}

	SNIC_INFO("Trace Facility Disabled.\n");
} /* end of snic_trc_free */